His not blood related little sister has been a professional illustrator for several years and is only 12 years old.
He has been a professional light novel author for 4 or so years and is only 15.

I'm not saying that this is not possible, but at least make it a bit more realistic. Especially that anonymous shit and him not even knowing who his illustrator is, is just bullshit.
And the part about him being to afraid to read comments about his work made me really mad.
Also, his reaction towards the comments about his handwriting, really?

Chaos' English and grammar hasn't improved in the least and that makes it even worse.

Now you have been a bit spoiled, too bad that it seems to be popular and the anime is, more or less, inevitable.